Valve structure



July 7, 1959 VALVE. STRUCTURE Filed June ,6, 1956 INVENTOR. CHARLES. K. uu'msmmsk.

' c. K. HUTHSING, sR' 2,893,687

United States Patent 1 VALVE -STRUCTURE aChai'lesK. Huthsiug, Sr., Culver City Calif.

Application June 6; -1956,''Sei'ial- Nu; 589,804

-- 4.laims. (Cl. -2517357) i i-This invention:generally-relates to-a va1ve=-structure and more particularly to a:valve structurewhich:is prefe'rably employed .as a' plunger assembly in! a-fire extin- 'guisher headconstruction- For this reasorrgthe invention will'be described'from the" standpoint of itsembodi- -mentin a portable fire extinguisher-3' altliough it will be appreciated that this novel valve structure maylbe ad -'-*=-=rvantageously employed othersimilar-applications.

'-It :is common practice in the-constructioi1 ofi many types of portable fire extinguishers and other valved dis- 1 -pensing structures toinclude -aplunger within the head assembly-adapted -to be m anually-actuated in order to .sealing device attached to its lower --end. -:The sealing device is usuallybias'ed -to seat=within the-extinguisher head and normally prevent the discharge-of the:pressur- PiZed' -cOntents of the extinguisher or tankL When the H extinguisher is to be'oper'ated, the" rod is forced 'downwardly by a handle or the like to cause the sealing device to unseat and provide a passageway for the escape of the powdered chemicals or liquid within the-tank.

It is thus-apparentrthat the-plunger assembly must effectively seal oif the contents of the extinguisher tank i during' longperiods of non-use of the extinguisher in order that theoperator -m-ay beassured,' under= emerhave been-encountered in-an attempt to properly-develop vi a -plungerrodandsealingdeviceof a simple construc- '45 which will properly maintain an ellective seal. The probs tion; which may be..inexpensivelyimanutactureddand yet lem is additionally complicated by the fact that the sealing device must be maintained in its seated position with a relatively small spring force in order to permit quick release by manual actuation.

It is, therefore, an object of the present invention to provide a valve structure of a form particularly adaptable to embodiment in a fire extinguisher head assembly, which is of a simple construction and yet of a design enabling an eifective seal over an extended period of time.

Another object of the present invention is to provide a valve structure for incorporation in a fire extinguisher head assembly, which is constructed such that it will maintain an efiective seal with only a small amount of spring force and which may be readily released in order to bring about a rapid discharge of the contents of the extinguisher tank.

Briefly, these and other objects of the present invention are attained by providing a valve structure or a plunger assembly combination comprising an elongated rod having a reduced diameter stem extending from one end. A plastic seal (or seal formed of material having equivalent properties) is provided which has a bore adapted to receive the stem. The bore is closed oil at one end within the seal so that the seal completely endischarge the contents of the tank; The plunger :assema bly conventionally comprises an elongated rod-with a gencyeconditions,-that-proper -pressure has been maintained within the -tank.- -Manytroublesome difiiculties 2,893,687 Patented July 7, 1959 entinvention-isdesigned to be an improvementov'er the r 4.5 1

seal shown in applicantsco-pending applicatione'ntitled Pressurized 'Fire Extinguisher"-*filed' August 23, 1955,

and identified by-Serial- Number*530,( 24,nowPatent No.-*'- 2,864,45-1, of Dc. 16; 1958; In-that application, -it will be noted that the sealing-material is preferably --formed of amaterial thatwill' cold flow underpressure. Although such' amaterial (for example; "T-efl0n) is-extremely desirable because of itsability to'*-provide a durable-gas-tight valve; a'-"p'roblem-is encounteredin endezivoring tdprevent -undesirableflow of theplastic ma- 15 teriall *Thusysomettype 'ofretainer -must be'used; and yet the structural'relationship between the retainer and the-plastic seal-mi1st be "such= that-no' leakage" willoccur. -'Insoine instances; leakage 'could*occur between the stern and the seal bypassing-downbetween theretainer and seal and thereafter upjalong the stem.

'It isy'th'erefore, a stillfurthef object of 'the present invention tcrprovide a structuralrelationshipbetween the retainer and the seal of the plunger assembly-of the present inventiorr'which isefiective-to prevent any-leakage therethrough.

A better understandingof the present invention will be-h'ad by reference to the-d-rawing's;showing-apreferred embodiment 'of the invention, inwhich:

' Figure -1"is a'fragmentary"sectional'view through a typical fireextinguisher head showing the valve struc- "ture -or 'plunger assembly bf the present invention there- "in'jand, a

:Figfire?-2- isan"enlarged' view' of thelowerportion of the plunger assemblyshown' in=Figure 1;

7 With reference to the drawings, there is"shown in Figure la valve structure or plunger assembly 10mounted* within a 'typical' firdextinguisher head lll- -The head f 11"is,only"partiallyshown for the purpose ofdescribing and explaining the 'operation of the'plunger assembly 10 in one typical application. The head :11 includes a-lower internally threaded bos's =12 forco'nnection'to the upper portion ofa fireiextinguisher tahk Tnot shdwn)I The .head 11 is also provided withatlireaded discharge conduit ,13 connecting with a"chambe'r 14. With *such an arrangement;.upon downward actuation of the plunger assembly 10;-gases'orchemicals may pass tip-"from the extinguisher tank through the interior of the boss 12 and thereafter into the chamber 14 to pass outwardly through the discharge conduit '13. Normally, the plunger assemshown in Figure 1.

The plunger assembly 10 includes an elongated cylindrical rod 16 passing downwardly through a close fitting bore 17 within the head 11. The rod is provided intermediate of its length with an O ring 18 which forms a seal between the rod 16 and the bore 17, and thus prevents the escape of the contents up through the bore 17.

The plunger assembly is conventionally operated in most extinguisher constructions by a handle or other lever which is adapted to exert a force in the direction of the arrow in Figure 1 to thus overcome the opposing force of spring 15 and urge the plunger assembly 10 downward.

At the lower end of the rod 16 is provided an O ring 19 held between an upper flange 20 and a lower flange 21 to form a seal between the rod and the surrounding seat or side walls 22 of the head 11, as shown more clearly in Figure 2.

A stem 23 extends downwardly from the lower end of the rod 16 and is provided with radial projections 23' to be force fitted Within a bore 24 closed oil within a bly 10 is held in its seated position by a spring 15, as

flowing plastic, such as Teflon, as disclosed in the above referred to co-pending application of applicant. The seal 25 includes an enlarged conical head portion 26 which abuts against an annular ridge 27 extending'downwardly from the sidewalls 22 of the head 11. In view of the cold-flowing characteristics of thesealing material 25, the head 26 will tend to maintain constant contact wtih the encircling ridge 27 regardless of variations in the pressure of the spring 15 during extended periods of non-use of the extinguisher. It will be evident, however, that a double sealing a ction will be effected since the ring 19 will alsobe compressed between the side walls 22 of the head 11. v

Near the base of the seal 25 is provided an annular shoulder 28. A generally cylindrical metallic retainer 29 is shown as circling the main body portion of the seal 25. The retainer 29 is dimensioned with a diameter 7 portion such that it may be resiliently snapped in to slightly smaller than the maximum width of the base 1'.

position over the base portion of the seal so as to be restrained in axial movement between the shoulder 28 and the enlarged diameter head 26. The retainer 29 terminates at its upper end with an increased diameter I 1 cup section 30 partially enclosing the head 26 of the seal The cup section 30 of the retainer 29 performs an important function in that it tends to limit and at the same to pressure from the spring 15 causing engagement be-; tween the ridge 27 and the head 26 of the seal, the plas-- under pressure.

invention is, therefore, not to be thought of as limited to the particular structure disclosed for illustrative purposes.

What is claimed is:

1. A plunger assembly comprising in combination: a cylindrical rod having a first 0 ring located generally midway in its length; a reduced diameter stem extending from one end of said rod; a plastic seal provided with a bore to receive said stem with a force fit, said bore being closed oil at one end within said seal, said seal being generally cylindrical and having increased diameter base portions, at least one of said base portions forming an annular shoulder; and, a generally cylindrical metallic retainer at least a portion of which is adapted to resiliently encircle said seal, said portion of said retainer having a maximum width slightly less than that of said one of said base portions, whereby said retainer may be snapped into position over said one of said ,base' portion onto said annular shoulder. i I

2. A plunger assembly according to claim 1, in which the otherof said base portions constitutes an enlarged head, and in which said retainer is provided'withja cup shaped end dimensioned to encircle and partially enclose said head. .7

3'. A plunger assembly according to claim 2, in which said plastic seal has the characteristic of cold-flowing ,4. A plunger assembly comprising, in combination: a

, rod, a'stem extending from one end of said rod; a coldflowing seal provided with a bore to receive saidstem,

said bore being closed off at the end within said seal;

tic material in the head 26 would normally tend to flow portions with a greater maximum width than said poraxially downwardy and radially outwardly. the cup section 30 prevents to a great extent such-flow,

whereby proper sealing contact is maintained betweenpressure of the spring 15.

It will be evident from the constructionlemployed,

I that no gases can leak between the stem 23 and the seal- 25 since the stem 23 is completely enclosed within the; seal 25. In addition, a structure is provided which is -,'i

extremely simple to manufacture and yet which is effec- However,

a metallic retainer at least a portion of which is adapted to resiliently encircle said seal, said seal having base tion of saidmetallic retainer, whereby said metallic retainer may be snapped into position by forcing said rethe ridge 27 and the head 26, despite variations in the -Ret23,142

' .tainer over one of said base portions.

References Cited in the file of this patent UNITED STATES PATENTS Allen Aug, 23,1949

2,001,487 Doherty May 14, 1935 --,2,608,210 St. Clair Aug. 26, 1952 2,641,278 Eplett June 9, 1953 2,666,614 Grove Jan. 19, 1954 2,776,104 'Sinkler Jan. 1,1957

Nurkiewicz J uly 2, 1957 

